Department of Biomedical Engineering, Graduate School of Medicine, Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, Nagano, 380-8553, Japan.
Bioengineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Anal Sci. 2021 Mar 10;37(3):461-465. doi: 10.2116/analsci.20SCP04. Epub 2020 Dec 4.
We prepared microspheres densely covered with oligo-DNA strands by immobilizing amino-terminated oligo-DNA strands on the surface of carboxylate polystyrene latex (PS) particles via the amide bond formation. The obtained microspheres (ssDNA-PS) stably dispersed in neutral pH buffer containing high concentrations of NaCl. For the ssDNA-PS ≥1 μm diameter, only 3 - 5% of surface-immobilized oligo-DNA could form a duplex with the complementary strands. Nevertheless, the resulting ssDNA-PS showed a distinct duplex terminal dependency in their dispersion behavior under neutral pH and high NaCl conditions; the microspheres with fully-matched duplexes on the surface spontaneously aggregated in a non-crosslinking manner. By contrast, the microspheres with terminal-mismatched duplexes remained dispersed under the identical conditions. These results suggest that the micrometer-scale particles covered with oligo-DNA strands also have high susceptibility to a duplex terminal sequence in their dispersion property, similar to previously reported DNA-functionalized nanoparticles. This property could potentially be used in various applications including analytical purposes.
我们通过酰胺键形成将氨基末端的寡聚 DNA 链固定在羧酸盐聚苯乙烯乳胶 (PS) 颗粒表面上，从而制备了寡聚 DNA 链密集覆盖的微球。所得微球 (ssDNA-PS) 在含有高浓度 NaCl 的中性 pH 缓冲液中稳定分散。对于直径≥1μm 的 ssDNA-PS，只有 3-5%表面固定的寡聚 DNA 能够与互补链形成双链。然而，在中性 pH 和高 NaCl 条件下，所得 ssDNA-PS 的分散行为表现出明显的双链末端依赖性；表面具有完全匹配双链的微球在非交联方式下自发聚集。相比之下，具有末端错配双链的微球在相同条件下保持分散状态。这些结果表明，寡聚 DNA 链覆盖的微米级颗粒在其分散性质中也对双链末端序列具有高敏感性，类似于先前报道的 DNA 功能化纳米粒子。这种特性可能在包括分析目的在内的各种应用中得到利用。
